Yo-yo tricksters, sky divers, ham radio operators, scuba divers, swing dancers, authors and bee keeers.
ALL OF US USE BITCOIN.
Sounds like he should get onboard already.
Discussion
It's not really like this tho is it? Yes we have all these groups, but would you say there is a lively community of skydivers, talking about skydiving in-depth, consistently and meaningfully?
The overall nostr vibe seems to be bitcointwitter chatroom -style posts and not topic posts. That is the main impression it gives too, which is why most people complain about this.
I do think Homesteading and Meshtastic are way ahead of other other subcultures/circles. I think you could invite someone interested in either of those and they would find a fair amount here in terms of community and conversations.
I don't think you could say the same for skydiving, or many many other topics.